We plan to characterize the molybdenum cofactor after we have learned to stablize it. Molybdenum transport into the cell and other reactions involving molybdenum also will be examined. We have identified a molybdenum storage protein and we shall purify it and attempt to put molybdenum on to the apoprotein. An in vitro system will be developed for assaying the transposition of molybdenum from the storage protein to the cofactor. By deletion mapping and complementation experiments we should be able to determine the exact location and the number of genes involved in the synthesis of the molybdenum cofactor. An understanding of the regulation of these genes also should be gained from this work. BIBLIOGRAPHIC REFERENCE: Pienkos, P.T. and W.J. Brill. 1976. Molybdenum uptake in Klebsiella pneumoniae and Azotobacter vinelandii. Abst. Annu. Meet. Amer. Soc. Microbiol. p. 164.